1. Field of the Invention
The present invention relates, generally to apparatus for handling documents, currency bills and the like. More particularly, this invention relates to an improved bill transport and stacking mechanism for use with document handling machines such as currency recognition units which are capable of automatic discrimination and counting of currency bills of different denominations.
2. Description of the Related Art
Automated currency handling systems have undergone rapid advancement in recent years, with respect to both sophisticated recognition techniques as well as the mechanical apparatus and physical configuration specifically adapted for implementing the increasingly advanced recognition and counting schemes. Top-of-the-line currency recognition units ("CRUs") are presently available which are capable of identifying and discriminating between and automatically counting multiple currency denominations at extremely high speeds.
Currency discrimination in modern-day CRUs is generally accomplished by optical sensing based on detecting and analyzing variations in light reflectance or transmissivity characteristics which occur when a currency bill is illuminated and scanned by a finely-defined strip of focused light. The subsequent currency discrimination is based on the generation and comparison of sensed test characteristic patterns with prestored master characteristic patterns for different currency denominations.
One exemplary and particularly advanced currency recognition unit (CRU) apparatus is disclosed in Raterman et al. U.S. patent application Ser. No. 07/475,111, filed Feb. 5, 1990, entitled "Method and Apparatus for Currency Discrimination and Counting", assigned to CumminsAllison Corporation, the entity to whom all patent rights in the present application are also assigned; the disclosure in that application is incorporated in its entirety herein by reference.
In a CRU system of the type disclosed in the above-noted Raterman et al. application, currency bills positioned at a bill accepting station are acted upon by a bill separating station which separates one bill at a time for being sequentially relayed by a bill transport mechanism, according to a precisely predetermined transport path, across an optical scanhead where reflectance characteristics of the bill are studied. Scanned bills are then transported to a bill stacking station where processed bills are sequentially stacked for subsequent removal.
The transport path is implemented in the form of a tri-sectional unit including an input path where bills are moved along a first direction in a substantially flat position, a curved guideway where bills are accepted from the input path and guided in such a way as to change the direction of travel to a second different direction, and an output path where bills are moved in a flat position along the second different direction across currency discrimination means located downstream of the curved guideway. At the end of the transport path, the CRU system is provided with a platform surface adapted to accept currency bills processed through the currency discrimination means for being delivered to a stacker plate where processed bills are stacked.
Typically, the stacker platform includes an angular surface on which are disposed a pair of stacker wheels which are formed of flexible blades and are supported for rotational movement in such a way that the blades of the stacker wheels cooperate with the stacker platform to pick up currency bills delivered thereto and deliver such wheels to the stacker plate.
Under operating conditions, a currency bill which is delivered to the stacker platform is picked up by the flexible stacker blades and becomes lodged between a pair of adjacent blades which, in combination, define a curved enclosure which decelerates the entering bill and function as means for supporting and transferring the bills from the stacker platform onto the stacker plate as the stacker wheels rotate.
CRU systems of the above-summarized type function efficiently with standard, normal currency which is not unduly curled. However, where currency bills being processed have been substantially curled, for various reasons including the manner in which bill stacks are handled by users, bank tellers, and the like, significant problems are encountered in efficiently transporting processed bills from the output end of the transport path to the stacker wheels and, hence, onto the stacker plate.
More specifically, as a curled document or currency bills goes through the CRU transport path, it is held flat against the action of some form of belt/roller bias arrangement so that the curling action of the bill is effectively countered. However, as the bill makes the transition from the end of the transport path to the stacker platform, the leading edge of the bill remains unrestrained for the transitional distance between the end of the transport path and subsequent contact with the flexible blades on the stacker wheels. In the absence of any flattening restraint exerted upon the bill, as it leaves the transport path the curled bill, immediately begins to conform to its original curled shape. As a result, the bill is likely to curl away from the stacker platform so that the leading edge of the bill is totally prevented from making any contact with the stacker wheels. Accordingly, such bills are never received by the stacker wheels and "fly" out of the CRU apparatus.
There, accordingly, exists a need for provision of means adapted for use with conventional CRU systems which are capable of counter-acting the inherent curling action associated with substantially curved bills and the like, so that effective stacking of curled bills may be realized by insuring controlled transfer of currency bills from the transport path to the stacker wheels and the stacker plate.